By Olivia Le Poidevin, Klaus Lauer, Johnny Cotton and Cecile Mantovani GENEVA, Dec 4 (Reuters) - Israel was cleared on Thursday to enter the 2026 Eurovision Song Contest by the organiser, prompting Spain,

Eurovision is facing its most serious crisis in the history of the contest, experts have warned, as more countries consider joining Ireland, Spain, Netherlands and Slovenia in boycotting the event.

The walkout by Spain, one of the "big five" backers of the contest, and two of Europe's wealthiest countries, raises the prospect of less sponsorship income and viewers for the extravaganza that draws...